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The errors that occur during runtime after compilation are called exceptions. To handle and rectify these errors, it is necessary to understand the cause and the point where the error occurs. There are two ways to find the details of the exception: one is the printStackTrace() method, and another is the getMessage() method. Both are used for exception handling in Java, but they are different from each other. Let's discuss how. The printStackTrace() Method The printStackTrace() method is defined in Throwable class of java.lang package and it is inherited into both java.lang.Error class and java.lang.Exception class. When you use it ... Read More
We can use the datetime module to convert a datetime to a UTC timestamp in Python. If we already have the datetime object in UTC, then the timestamp() function can be directly used to get a UTC timestamp. This function returns the time since epoch for that datetime object. If we have the datetime object in the local timezone, first replace the timezone info and then fetch the time. The following are the various methods to convert a datetime object into a UTC timestamp in Python. Using datetime.timestamp() with UTC-aware datetime Local ... Read More
In Python, the mktime() function (from the time module) assumes that the passed tuple is in local time, while the calendar.timegm() (from the calendar module) assumes it's in GMT/UTC. Depending on the interpretation, the tuple represents a different time, so both functions return different values (seconds since the epoch are UTC-based). The difference between the values should be equal to the time zone offset of your local time zone. Understanding time.mktime() in Local Time Context The Python time.mktime() method converts the object form of local time into seconds since the epoch (January 1, 1970, 00:00:00 UTC). This method is the inverse function of localtime() and ... Read More
In Java, Jackson is a library that is used to convert JSON to Java objects and vice versa. Jackson Annotations are used during serialization and deserialization. We use these to denote or specify annotations before a particular field or method (that is declared in Java). Using an annotation before a field, we can denote whether it is a variable, is a JsonProperty, should be ignored, or what condition should be applied to it. So basically, Annotations make JSON output clearer as we required. In this Article, we will learn about ... Read More
Jackson is a Java library that is used to convert JSON to Java objects and vice versa. Conversion of JSON to a Java object is called deserialization, and Java object to JSON is known as serialization. Both of these tasks can be done by using the Jackson library. In this article, we are going to learn how to convert JSON to Java objects using the Jackson library. Jackson Library: Convert a JSON to a Java Object The ObjectMapper class belongs to the Jackson library. This class is responsible for the serialization and deserialization of Java objects. The ObjectMapper class is used ... Read More
To check if an ArrayList contains a specific item, we can either compare each element with the given item and print the result if they are equal, or use a predefined method that directly checks for the containing element. ArrayList in Java In Java, an ArrayList is a class similar to an Array, but unlike an array, it has a dynamic size that automatically increases or decreases, depending on the number of elements added or removed from it. Following is the syntax for creating an ArrayList in Java - ArrayList list_name = new ArrayList(); Here, ... Read More
A list stores a sequence of elements of a similar type. Like an array, the elements in a List are stored at specific indices, starting from index 0. The 0th index indicates the "first element", the 1st indicates the "second" element, and so on. In Java, a list is represented by the interface named List (with the same name) that extends the Collection interface. To create a List object, we can instantiate any class that implements the List interface, such as ArrayList, Stack, Vector, etc (Since we cannot instantiate an interface). We can get the first element of the List in ... Read More
Python has a built-in method called values() that returns a view object. The dictionary values are listed in the view object. We can use the values() method in Python to retrieve all values from a dictionary. Python's built-in values() method returns a view object that represents a list of dictionaries containing every value. In this article, we are going to see about the various ways to print all the values of the given dictionary in Python. Using dict.values() Method Python's dict.values() method can be used to retrieve the dictionary values which can be printed using the print() function. Example Following ... Read More
A binary tree is a non-linear data structure where each node can have at most two children i.e. left children and right children. In this article, we are going to discuss how to count nodes in a complete binary tree using JavaScript. What is a Complete Binary Tree? A complete binary tree is a binary tree in which all the nodes are completely filled except possibly the last level of the tree, and the last node has all its nodes on the left side as possible. Below are examples to demonstrate the above problem, clearly: Example 1 Input: ... Read More
In Python, the try, except, and else statements are used to handle exceptions and define specific blocks of code that should execute based on whether an error occurs or not. This helps you manage errors and separate successful code from error-handling logic. Using "try" and "except" The try block contains code that might raise an exception. If an exception occurs, the control jumps to the except block, which contains code to handle that exception. Example: Handling division by zero In the following example, we are dividing a number by zero, which raises an exception that is handled by the except ... Read More